New tetracyclic triterpenoids from Jatropha gossypiifolia induce cell-cycle arrest and apoptosis in RKO cells.

Four new tetracyclic-type triterpenoids, jatrogossols A - D (1-4), along with 5 known analogues (5-9), were isolated from the ethanol extract of the branches and leaves of Jatropha gossypiifolia. The absolute configurations of 1-4 were defined by using a combination of electronic circular dichroism data analysis and single-crystal X-ray diffraction data. The cytotoxicities of the triterpenoids were evaluated using RKO and HepG2 human cancer cell lines. Compound 8 was cytotoxic against RKO colon cancer cells with an IC value of 12.5 μM. The morphological features of apoptosis were evaluated in 8-treated RKO cells. Compound 8 effectively induced apoptosis of RKO, which was associated with G or S phase cell cycle arrest. Flow cytometric analysis showed that treatment with 8 significantly induced RKO cell apoptosis in a dose-dependent manner.